Hydraulic piston



Jem.V 7, 1930. G. P CRONER 1,742,582

HYDRAULIC PIsToN Filed Feb. 11, 1929 A INVENT-ok.l 6601781. Grnen Patented `lan. 7, 193

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Application led February 11,. lSerial: No. 339,252.

K'lhisfl inventionrelates: to a hydraulic piston particularly adaptedf for use in connection with automatic Inud` pumps for rotary drillinggrigs: Y 9 5@ 'Efe primary object of the invention is to proaride, in a. manner as hereinafter set. forth, arpistorrofx thecl'ass aforesaid wherein a liner is expanded by fluid pressure to firmly seat l against the eyli-nder wall? and whereby such 1Q lnidiscontrolled by an automatically operating Vaima thereby maintaining an` even" pressurey on.- the liner at Varying pressures of the fluid. y l y l With. these and other objects in View, the

combination andV arrangement of parts as hereinafter more particularlydescribed, and

asillustrated in the accompanying drawings wherein'is shown a. preferred embodfimentof :1 20 theiiwentiombut it is to bewunderistood that snchrdrawings. and descriptionsare to be talien as illustrative and that thel invention .is inf claims hereunto appended. y Y

2,5 Inthe. accompanying drawings in which A like numerals arev employed' to designatelike pants. througho uit4 the -samer- V y re.1 isa vertical section through .apistonconstructed in. accordanoewith: this invention. Y .A i y. y

Figure2 is a section taken on line 2-2 tendedtobe limited only the scope of the' figure 3 is a section takken,on.line-j-wV of" Figrnre2.. y ,t A 35; igure 4f is a View'of the pistonjin end` ele- ""vation. Figure 5l is a fragmentary sectional -pl'an' thereof.,` i y i v Referringto the drawings in detail; A rep- 4Q resentsa piston consisting of an? inner lsection A B-` and an outer section CI The innersection' B" consists ofa substantially cylindricallbody portion 1 haVi-ngan annular flange-2'formed integrally at one end'thereoi". The outer sec- 45 tion Gis adapted tofseatagainst thefoppos'ite endA of the body portion 1 and the outer periplieral' portion 'tliereoffformsfa counterpart ofthe llangev2' whenithefsectionsare inrassembled relation. Extending transversely through. sections and LC is a tapered bore invention consists ofthe novel construction,-

gr0oves-12and 1?3 means. of' a passageway and. between the grooves 12 and 14 by of the section Bisformed with ajsi'milarlrei cess 7.' Spaoedfrom. the peripheral edges V60 y thereof, the opposingfaoes of thefflanzgfe 2 andi` outer section C are formed with opposing annular recesses 8 for the reception thereiniof apair of outwardly directed flanges 9 vand", 10 formed fon ani annularlinerll. Y The `65 linerlfrl ispreferably formedof'rubber andV is. seated-)on the body portionfl*between the opposing?, faces-- of the flange 2V and` outer section C. Formed inthey periphery of'vtl'ie bodyportion .1, centrally'thereol is a cir- 70 cumferentially extending groove 12,. and onopposite. sides of the lgroor/'eV 12 are, similar Y grooves respectively indicated at 1'3.-and 141. A Communication f is established' y y between the means of a similar passageway 16f The passagewaysfl! and 16 are odset with respect to eachothen .Y

Formed within the body portion 1isV anan- 80 nu-lar elamberf'whicli is disposed concen- Y u trieally oft-hefbore Sin spaced relation therel.y to.Y The inner,walli'offthe'cliamber 1'7 is offset, as ,indicated at 18, whereby the chamber lZisformed withY a forward end' portion v19 of greaterdepththan -th'e rearward endv portion 2O;V 'The outer Wall of the chamber 1T has an opening 21 extendingtherethrough,'by means ofwliieh'eommunication isest'ablishedj between thet interiors ofthe chamberl?" and groove'1'2lw" `llidending longitudinally of the' piston andv disposedfwithin the` forward end' portion 19' `ltdk plug 22 is formed with an internal, Vbeveled shoulder 24. Spaced from the rearward end thereof, the plug 22 is provided with a hexagonal exterior surface 25 in order that a suitable tool may be supplied thereto `for threading the plug into the outer `section C ofthe piston.

Slidably mounted within the plug 22 is a tubular member 26, which is formedintermediate its ends with a beveled shoulder 27 for seating against the beveled shoulder 24 of the plug 22. Slidably mounted within the forward end of the member 26 is a guide 28 of skeleton construction, which has secured to its rearward end a valve 29. The valve 29 is Vformed with a tapered forward face for seating against the inner face of the shoulder27 when the guide 28`is moved forwardly Vwith respect to the member 26'. lThreaded in the rearward end of the member 26 is a cap 30, which is formed at its rearward end with a flange' 31 bearing against the rearward end of the member 26. r Y

VA. .knob k32 is provided on the rearward face of the valve 29 'for maintaining the latterin spaced relation to the spring 30 to prevent sticlring of the valve.l The member 26 is normally maintained with the shoulder 27 Y seated against the shoulder'24 of the plug 22 by means of a spring 33, one end of which abuts against a cap 34 threaded in thel rear-V ward end of the plug 22, and the other end of which abuts against the cap 31.4 The tension of the spring 33 may be varied as desired vby manipulation of the cap 34. Communication is established between the interioisof the chamber 17 and plug 22 by lmeans of an open- 1 ing 35 formed through the vwall of the plug.

The wall ofthe member 26 is formed witha plurality of spaced ports 36, 37 and 3.8, which,`

are adapted to be selectively registered with the opening 35. The port 36 is materially' larger than the port 37 and the latter is mate-` rially larger than the port 38. With any one of the ports 36, 37 and 3S in registry'with the opening 35, communication is establishedy between thel interiors of the chamber 17 and tubular member 26. I

Extending through the vbott'omwall of the annular recess 6is`acirc`ular opening 39 by meansof which an inlet is provided to the interior of the ,member 26.", `Spanning the mouth of theopening 39` i s ahcard 40 which 4provides a screen for the opening. Y -Relative rotary movement is prevented between the tubular members 26 and plug 22 by means of rection until the port 36 is brought into registry with the opening 35 as illustrated in Figure 2. With the port 36 and opening 35 thus in registry, the fluid may pass into the chamber 17 and through the openings 21 into ways 15 and- 16 to the grooves 13 and 14. The pressure is'thus transmitted to the inner sur- Vthe grooves 12, thence through the passage-l face of the liner 11 which forces the outer' surface of the latter aga-inst thei'nner'wall of the cylinder within which the piston is operating and therebyfprovides a seal between the piston and inner wall of the cylinder.

lVhen theV pressurevof the fluid increases to a predetermined point, the spring 33 is compressedV which permits themember 26 to be moved in a rearward direction with respectY to the plug 22. Upon movement ,of the m'e'm-` ber 26 with respect to the plug 22,.the port 36 is brought out of registry with the opening 35 and the port 37 isbrought'into registry therewith.` Due to the lesser area of the port 37, the pressureof the iuid against the liner 11` is the same when thevfluid "isv passedV through theport 37k and opening 35 as'when itis passed through the port 36 and openingl Upon a further increase of pressureof the fluid entering through the openingsv 39, the spring 33 is further compressed andthe port 37 is brought out of registry with the opening 'andthe port `38l brought into registry therewith. Due'to the decrease inarea of the port 38 over that of the 'port 37 ,1* the pressure against't-he inner surfacev of thelinerl 9 remains* unchanged. {Upon the return stiolre'of the piston A, the valve 29is drawn by suction into engagement with theishoulder 27 whereby the inletnto theirrlember 26l is*k closed. i f

It is thoughtthatthe many advantages of a piston in accordance with thisI invention will be Vreadily apparent-,pand althoughthe preferred embodiment `is Vasillustrated and described, yet .it p is to be understood thatv changes may be mad'e in the details of conics struction, which fall within the scope of theV invention as defined in the i y, appended claims'. f WliatI claimis: 1 f

1. In a device of the character described,

a'piston formedy with a peripherally extending recess and a concentrically arranged, ani

nular chamber, the bottom wall of said recess having a groove in communicationwithsaid l chamber, a hollowV plug within the chamber A and anchored at one end .to thepiston, the wall of said plug having an opening into said chamber, a tubular member slidably mounted withinthe plug and: formed with a plurality of spaced ports'fo'r progressive registration with said opening, means to providean inlet to the interior of the tubular member fromv the exterior lof, the piston, and` pressure op-'v era-ted Valve for said inlet.

i described, a

2.V In a device'of'the character piston formed with a p'eripherallyextending f recess and a concentrically arranged, annular chamber, a hollow plug within the chamber and anchored at one endf'to the piston, the wall of said plug having an openinginto said chamber, a. tubular member slidably mounted within the plug and formed with a plurality ot spaced ports for progressive registration with said opening, means to provide an inlet to the interior of the tubular member from the exterior of the piston, and a pressure operated valve for said inlet, the bottom wall of said recess further having a pair of spaced grooves in communication with said Vfirst named groove. Y

3. In a device of the character described, a piston formed with a peripherally extending recess and a concentrically arranged, annular chamber, the bottom wall of said recess having a groovein communication with said chamber, a hollowA plug within the chamber and anchored at one end to the piston, the wall of said plug having an opening into said chamber, a tubular member slidably mounted within the plug and formed with a plurality operated valve forsaid inlet, said ports having graduating areas withl respect to each other.

6. In a device of the character described, a piston formed with a peripherally extendn ing recess and a concentrically arranged, an nular chamber, the bottom wallof said recess having a groove in communication with said chambera hollow plug withink the chamber and anchored at one end to the piston, the wall of said plug having an opening into said chamber, fa tubular member slidably mounted within the plug and formed, withV ports of graduating areas, one `oi saidports normally registering with said opening,

means to provide an inlet tothe interior of.

the tubular member fromthe exterior of the piston, a valve for controlling said inlet, and

means whereby a pressure on said valve actu-l ates said tubular member to progressively register said ports with said opening. Y

In testimony whereof, I aix myl signature hereto.

GEORGE P. CRONER.'A g

of spaced ports for progressive registration with said opening, means to provide an iinlet to the interior of the tubular member from 340 the exterior of the piston, a liner seated within the tubular member from the exterior of the z `operated valve for said recess, and a pressureoperated valve for said inlet. Y

4. A piston formed of an inner section and an outer section, said inner section including a cylindrical body portion having a flange formed integrally at one end.. said outer section seating against the opposite end ot said body portion, said body portion ormed'with a concentrically arranged, annularv chamber progressive registrationwith said opening,

means to provide an inlet to the 'interior `of piston, and a pressure said inlet. y

5. In a device of the character described, a piston formed with a kperipherally extendnular chamber, the bottom wall of said recess having a groove in communication with-,said chamber, a hollow plug within the chamber and anchored at one end to the piston, the Y wall of said plug havingan opening into said chamber, a tubular member slidably mounted.

of spaced ports for progressiveregistration with said opening, means to provide an inlet vto the interior of the tubular member from` the exterior of the piston, 'v and a rpressure ing recess and a concentrically arranged,'an'

within the plug and formed with a plurality 

